


A Birthday Surprise

by Lady_Fairy_Moth



Category: Undertale (Video Game)
Genre: Advice, Attempted Seduction, Birthday Presents, Birthday Sex, Ecto-Genitalia (Undertale), Ecto-Penis (Undertale), Ecto-Tongue (Undertale), F/M, Fluff and Smut, I get bored?, I write smut, Lemon, One Shot, Seduction, Short One Shot, Smut
Language: English
Status: Completed
Published: 2019-12-21
Updated: 2019-12-21
Packaged: 2021-02-26 00:21:56
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings, No Archive Warnings Apply
Chapters: 1
Words: 3,342
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21884440
Author URL: https://archiveofourown.org/users/Lady_Fairy_Moth/pseuds/Lady_Fairy_Moth
Summary: I have tried everything. But all he keeps doing is shortcutting away. Not this time, he won't get away from me. This I got advice, and I got a plan.Depending on your mood, you can put yourself in Frisk's place. Read the tags and note the rating.
Relationships: Frisk/Sans (Undertale), Sans (Undertale)/Reader
Kudos: 37





	A Birthday Surprise

**Author's Note:**

> Author note: I promised this lemon one shot. I was very bored and angry. Tumblr is horrible, and the purge angers me. I came up with this plot almost two years ago and gave it to a patented smut writer. Who never wrote this fic. I felt to much shame to write this fic. Yeah, I can actually feel shame. If the idea is good enough and detailed enough for it to work. This is going to get pretty explicit and racy. Raunchy. Theirs’s some plot with this porn, but what can you expect from me? That’s my schtick. I love a good plot. Most of the one-shots I’ve written I did with the thought in mind to release something that was bugging me and wouldn’t let me rest unless it was finished. With this, it’s more like the protest of unjust treatment and not allowing free expression. Censoring art, but not Nazi and porn bots Tumblr screwed up royally. I hope they are paying for it right now. If you like this story, please remember to subscribe to me as a writer because it’s called a one-shot it’s a whole story. Leave a kudos or a comment. Hell, bookmark it if you think this story is worth that much attention, but please don’t wait on another chapter to this fic because it’s never coming, and I hate seeing subscribers to a one-shot it makes me sad that someone would wait on a story that’s already done. Hell, if I see one, I know that just another person who doesn’t see the note proving my point. I own nothing the game Undertale belongs to Toby Fox.

Frisk’s Perspective

Walking to their home was never that big of a deal. But visiting them is always hard to do when I’m so busy. The last time I was home was during Christmas, and it’s almost Easter now. I haven’t made any progress. While I have furthered the cause of monsters being given rights that all sentient beings. I’ve gotten a lot done, and now most monsters are allowed to live in peacefully in any city in the world within reason places that have a dictatorship or isolationist borders aren’t and refuse to allow monsters on their lands. I was able to secure them any job they are qualified for and the rights granted to most sentient beings the few left on the docket being marriage rights both between monsters them and between humans and monsters. I’m rarely home long enough to kick back and take a breather, so two weeks off is more than enough for a vacation. But progress with the monster I love?

I am making him see me in the light that I need him too. Impossible, we’ve been stuck in the friendship stage for way too long, and I have had feelings for him since I went off to college with the dream of being a political science major and ended up getting a law degree to boot. That was six years ago, and I would text him every day, face cam and video chat every single day. I flirted with him with the intensity I still haven’t stop blushing about? But no dice! He never took the bait. I’ve done it in person? Nada, and I’ve tried so hard! I’ve done everything I can think of. I need advice from my friends. I’ll take any and all advice from anyone at this point! Anyone who might have an idea and might get me a new perspective and tactic. There’s no one who has unique ideas and scenario quite like Alphys and Undyne. Between the two of them, I’m bound to find something I can try. I already texted them to let them know I’m coming over.

After the last time, I showed up unannounced better safe than sorry with these two. Though I want more than anything, someone to give me some direction. Why did I have to fall in love with Sans, huh? I knock on the door, moving impatiently. I was nervous. I had kept it a secret from most of my friends. No one knew who I was interested in. Sometimes I would date both to try to get over him and give some form of normalcy. I became somewhat a celebrity for what I did and my position now. Allowing the pictures are better than fighting them off constantly; the more you avoid them, the more attractive you are. Now I get left alone like today.

“Come on in Frisk, Undyne is in the kitchen getting the snacks I already set up the tv.”

Taking me to their living room sitting on the couch as Undyne laid everything down and took place next to Alphys.

“Alphys, Undyne, I’m here for some advice. On a delicate subject and I need secrecy, and I don’t want this getting out.”

For my part I can feel myself glaring at them to keep their silence if I didn’t ask for it, I have no doubt both would blab, but I had no one else to turn to on this one. Anyone else wouldn’t have a clue or is too close, and it would be awkward. While Alphys and Sans are friends, they can be respectable about personal business, and Undyne was his boss and friend adjacent since she is best friend with Papyrus. She knows him well enough to give me an off the wall idea. Alphys is smart enough to know what he’s thinking without talking with him directly. She was the one who was able to somehow help Asgore woo Toriel back, and that’s saying something even I couldn’t do that. Alphys maybe a nervous monster, but she’s perceptive and notices what others would rather not state it overtly. So, asking them is both smart and risky because I’m asking them not to gossip about me or not share with their friends. But bring this up with mom would be weird, and Papyrus can’t keep a secret to save his life much less anyone else.

“I promise Frisk your secret is safe with me, I promise.” Alphys' eyes show a gleam of resolve like she was showing a lot of conviction about keeping this quiet.

“Yeah, punk, we both swear not to gossip. What did ya take us for untrustworthy?” Undyne looked slightly angry at the accusation but seemed like she would help anyway have a similar resolution as her fiancée.

“Look for a long time now I’ve had a crush on Sans,” I didn’t even get to finish for both of them started to squeal with Alphys all but fangirling about this in a way only she could.

“Calm down both of you, or I walk out of here, and I can get advice from a fortune teller.”

Alphys, for her part, started taking breathing exercises to calm down, and Undyne seemed to cover her mouth and close her eyes. Helping her calm down.

“I need help getting him to see me as an adult. I’ve been flirting with him for the last few years webcam; in person, I’ve done every flirtation technique I can think of I’ve used every strategy I can think of, and I still couldn’t make headway and getting him to notice me.”

“Have you tried being blunt, Frisk? Just tell him about you feel?” Alphys, for her part, was trying to be a rational, but it's hard to not want to pull my hair out.

“You think I haven’t tried that? Every time I get close, I tell it's important, and I need to speak with the shortcuts away or says he got to get his next job to get too. How many jobs does he have now? He doesn’t even need that much now, jeez?”

“I can see where you’re going with that punk. For a lazy bag of bones, Sans is a squirrelly one. He’s one to work multiple jobs but tries to ask anything personal, and he’s gone before you even had a chance to finish the first word. I’m starting to see the problem, punk. He could easily take off or get away. Plus, their no way to tell if he feels the same or that if he likes women, I’ve never even seen him on a date.”

“Undyne.” Alphys, for her part, seemed to give her a look, but I started feeling the weight of a lost cause.

“Sans doesn’t date much, but he did a long time ago before he threw himself into taking care of Papyrus. But he does have a soft spot for you.”

I felt the shock at her words, leaving me speechless. I could feel my mouth gaping like fish on land.

“Whenever you come back? you are, all he talks about when you get back from the diplomatic mission. The changes you had gone through and the jokes you made where the topics he always blushes and gets flustered. When I press or if he mentions something, you said something that shocked him. Which is rare for him, so he feels the same way. So, I have a plan for what you can do. I’m going to help you. You are the reason Undyne, and I got together after all. The least I can do is help you.”

I felt so confident Alphys gave me a ring to stop him from taking off, and Undyne gave me a seduction plan if it has to come to that. I have no regrets about bringing the fancy ketchup with me. Today was his birthday according to him, but he doesn’t want a party, and he just wanted a day off, and some solitude and Papyrus obliged. There’s no party today, and he’s home alone.

Knocking on his door, he opens his ever-present smile at the full view, but his pinprick shows surprise.

“I know that you said you wanted solitude for your birthday, but I’m rarely back home, and we’ve barely spent any time together. I got you a present and some fancy ketchup? Come on, let me in. I promise we can do what you want to do.”

“Fancy ketchup, you say? Come on, and I know you missed my humerus puns.”

“That I did, Mr. Funny bone. That I did.”

As I walked, I handed him the fancy ketchup closing the door. He had a bag of potato chips on the couch, some sodas, and several bottles of ketchup. He really had set up for enjoying his day off, his way being the absolute couch potato.

“Sans look, I want to be honest with my feeling with you.”

“Oh, Frisk, I just remembered that I picked up a few shifts at the hotdog stand; I’m so sorry to dine and dash, but I gotta go.” He walks out the door, but I standstill. I wait on the couch smirk; he’s not going anywhere.

“Why can’t I use my short cut, Frisk?”

“The ring on your finger while I did get it with you in mind, but I had it imbued with the magic of Undyne and Muffet, so you are trapped within the house. The perimeter that ring will come off in 24 hours more than enough time for you to talk to me. Sans? you have been avoiding this conversation for years, it ends now.” I could feel a hard edge in my eyes; there was a steely gleam in my eyes.

“Please, I’m so tired of this. ANYTIME! I want to talk about this? Running aren’t you too old for this.”

“Fine, you want to talk? Fine.” Sitting on the couch, pausing the movie on the screen, we were watching. I take my seat, facing him looking deeply into his eyes. Taking a deep breath

“I just want you. I love you; how much do you want me to tell you? How long that no matter how much I tried and fought? That my heart still yearns for you to feel the way I feel right now. Is how I feel right now I will feel it always feel till the day I die.”

Sans turned to me. I looked into his pinpricks, and they were hearts?! And a blush on his face, something screaming me to kiss his teeth since he didn’t have any lips. Plucking up the courage to kiss him, I go for before I lose my nerve kissing him with everything I have in my heart, hoping he kisses back with as much passion as I kissed him.

I can feel him pull me into his arms; it almost felt like I was kissing lips. I felt tingles on my lips. I could feel him groping my backside.

“Is that how you want it to be that. So, it be. I may not be able to hold back any longer.” Feeling him give as he snapped my bra after a few bad attempts at getting it off. The way his phalanges touch my back bare of the bra. As I threw my shirt over the couch, I feel my body shiver in anticipation. As he touched my breast experimentally, the pleasure enveloping me, and a small moan came out. I was already in his lap, so I couldn’t stop myself from shameless grinding against him. Sans started leaving tingling kisses on my neck. I could feel myself becoming lost in the fog of lust. Taking his shirt off, touching his ribs in a way even with my eyes closed. I felt the bright blue of his blush as he pinched my nipples. I felt a bulge underneath me as I felt him. He licked my shoulder up to my neck, leaving a love bite where anyone with eyes could see.

“We need to take this somewhere more special more private,” he whispers in my ear I feel my knees weak.

I felt a gasp as I found myself on his bed in a suspiciously cleaner room. My interest was piqued, and I was mystified into shock Sans took all the clothes off me before I could say a word, I laid bare before him, and the heart-shaped pinpricks were in larger in his sockets, and I felt my heart racing from desire. As he laid down next to me, every touch bringing me pleasure in a way I’ve never known. I try to take off his shorts, but he shakes his skull.

“I know you're impatient for the bone zone, but let’s enjoy this. I didn’t let you in much less allow myself to be with you now that I have you here? I want this to be something we both remember and could never forget.”

I felt my breath pick up; I was barely above panting. My heart was in my ear like a dream; my deepest wish his tongue slowly started tracing a path from my neck to the valley of my breast. Taking a torturous time circling my nipples in a way like he knew how to make melt in his radius and ulna. The desire within me to make him feel half of the pleasure I’m feeling right now. But I hadn’t noticed I was being held down by blue magic

“For your impatience, I want to see you drenched. I can’t do that if your trying takes my shorts off before you’re ready.”

Circling my areola in a way had me hissing to fight against his magic, and I felt his power increase. Massaging the other while giving me individual attention to one and switching back forth slowly. Letting them go finally after his tongue trailing a path down my body swirling my belly button moving lower moving between my thighs nibbling at my thigh playfully licking after every nibble a pleasurable shiver crawling up her spine.

“Look unraveled and inch from begging. I should change that.” His breath on my upper thighs, his teeth brushing, giving them a kiss.

His skull was getting comfortably between them and spreading my lips between his phalanges running his tongue between my slit all the way to my clit. I couldn’t hold back my pleas and praises, and the way he is building my body into a knot while he expertly builds up the orgasm in me, I can barely think the pleasure had taken my mind and my body.

“Like music to my ears now sing again. ”

I was sensitive, but like the expert, he seems to be he slid his phalange up my slit and curled it, and then I just saw stars burst beneath my eyes.

Rubbing his nasal cavity against my cheek, putting one of his ulnas under my legs, putting it on the shoulder blade.

Her curiosity overcoming the tranquil and weakness of the two back to back to orgasm she wanted to see, considering she wasn’t sure if this would be the only time. But if it’s is, she was going to enjoy this? She better make the most of this. Considering this might be her only chance at this. I Might as well make the best time for both of us. Pushing him off her to the rise of his brow bones pin him below me finger his clavicle and trying to see watch drove him wild at least to have that memory glowing in Sans’s mind. He seems to squirm, and the lower I went, especially when I would randomly kiss a bone or lick one that I had just touched. The bones were rattling, and he was being blue; I knew I was on the right track. Noting he was sensitive all over moaning when I touched his lower ribs softly stroked his vertebrae, thrusting his pelvis into the air. Bringing the objective back into focus. There it stood on his pelvis I always wondered what I might encounter if I ever got to see or if there was one. So, seeing it was a shock. And it stood I assume magic manifested and what kept it in place with slight strings attached to his pelvis and the tailbone.

Interesting tracing nonsensical patter on his pelvic bone, noting the rattling and the light gasps he was making. Drinking him, I was impressed. He was at attention a powder neon blue thicker than my hand and more than impressive in length. Noting the veins on the side and the way it leaked a little from what had already happened so far. Testing the waters may be pushing my luck. I licked his pelvis, provokingly swirling my tongue at the base of the penis in my hands. Thier was no real taste but pleasant tingle on the tongue at doing, so making me smile outwardly. This _is going to be a fun experiment indeed._ The moan was so soft, but; it urged me to keep pushing his buttons. Lick up and pop the tip in my mouth and swirling my tongue around it. The taste my mouth was nothing i had experienced before, but thier was hint od something sweet what it was i couldn't say I notice him gripping the bed holds tightly. He’ll crack soon enough. Lowering myself self, I could feel almost feel whatever grip of patience that he had seemed to unravel like he might have done to me. Taking pleasure from every moan feeling the last shred of restraint as he used magic to make me stop.

“Hey, now you don’t want to stop this before the best now, do ya?”

Putting himself in the position, he was in before looking into his pupils that were heart-shaped once again. I felt my heart racing, I could feel myself drenched at that moment I was more than ready, and I almost called out to him hurry up. When I felt the snap of his pelvis and sharp gasp came from my lips. I felt myself give in as Sans slow thrusting into me, looking into my eye, caressing my face the soft gasps leaving out of my mouth. The moans are increasing, but the slow rise was killing me. And I knew I just couldn’t let him to do all the work. Thrusting from below knowing that might shock Sans into speed up and to stop torturing me. After the second time, Sans finally catching to the pace change, and I felt myself lose myself, and so did Sans. The intensity of his thrusting was almost overwhelming. Feeling him switch the position the magic-making it easier. Want to give as much as she was getting thrust as a hard as Sans was thrusting into me. At that moment, it all seemed to crash together. The climax seems to make her freeze. Though the cry came out of her and sans was moaning alongside her. Curling up together in the afterglow.

The sun was rising. The window curtain allows a glimpse of the sight of dawn and two eyes, and two pinpricks seemed to look at each other with an intensity in their gaze that said everything and nothing. Unsure who should say what and who should speak first.

“Well, was it what you wanted? Everything you hoped for?”

“Sure,” She was under the blanket wasn’t looking at Sans but at the window.

“This isn’t a one-time thing, you know? If that’s why you won’t look at me. I don’t just take anyone to bone zone. Even then, keep in mind I could leave my hand. just shortcut out of here. You? My angel? I am yours for as long as you want me. And I hope you are mine for just as long.” He was blushing but felt better as she pulls her naked body on top of Sans.”

“Forever. Oh yeah, belated happy birthday sugar skull.”

**Author's Note:**

> Final note: I wrote this to work on my smut chops. I haven’t written like this in a long time. The last time was a year and a few months. Smut is an excellent way to plan things out. I need to be able to write this detailed for the main Frans fanfic I have to be able to do the same if not better. Also, I hope people would subscribe to me and not the fic. It’s the best gift anyone can give me. If you want to subscribe to a fic I’ve written? Give attention to Everything Stays, But It’s Changing. Shameless, but that’s why I can write smut. I need to be able to be shameless. To write a moment of unbridled passion with an almost clinical detachment, that’s my dream.


End file.
